The present invention relates to improvements in paper feeders for use in image forming apparatus such as electrostaticcopying machines and facsimile apparatus.
Paper feeders for use in image forming apparatus generally comprise a paper containing unit including a paper tray, and a feed unit having a feed roller for dispensing sheets of paper from the containing unit one by one. In recent years, the paper containing unit is made withdrawable in a direction perpendicular to the direction of transport of paper for the user to supply paper to the containing unit as withdrawn from the image forming apparatus forwardly thereof so as to reduce the space needed for the installation of the apparatus and facilitate the replenishment of paper. However, the paper feeder thus constructed has the following problem. When paper has jammed the feed unit, the paper containing unit is withdrawn to remove the jamming paper. The paper is then pulled sideways by the withdrawing movement and is liable to break to partly remain inside the apparatus. The remaining portion of the paper is cumbersome to remove.
As disclosed, for example, in Unexamined Japanese Patent Publication SHO 59-207333, paper feeders are already known which comprise a paper containing unit and a feed unit which are in the form of an assembly so as to be withdrawn at the same time, such that in an event of a paper jam in the feed unit, the jamming paper is withdrawn from the image forming apparatus forwardly thereof along with the containing unit and the feed unit and can therefore be removed without breaking.
When the paper containing unit of the disclosed paper feeder is withdrawn from the image forming apparatus forwardly thereof for the replenishment of paper, the feed unit having a feed roller is withdrawn as connected to the containing unit. Accordingly, the feeder has the problem that the feed unit becomes an obstacle to the replenishment of paper.
Further Unexamined Japanese Patent Publication SHO 63-212629 discloses a paper feeder which comprises a feed unit, a paper containing unit withdrawable together with the feed unit, and a guide portion for pivotally shifting the feed unit with the withdrawing movement to position the feed roller away from the paper containing unit when the feeder is withdrawn and to thereby facilitate the replenishment of paper. With this arrangement, the feed roller is still positioned above the paper containing unit, which therefore can not be replenished with paper with greatly increased ease. Moreover, when the paper containing unit is withdrawn for replenishment, the feed unit is also withdrawn therewith at all times, so that every time the containing unit is withdrawn, the feed roller must be uncoupled from the drive mechanism therefor and thereafter coupled thereto again. This procedure is cumbersome and further involves the problem that the gear or the like constituting the drive mechanism is prone to damage or break when the roller is coupled thereto.